A. Field of the Invention
The present invention relates generally to digital subscriber line (DSL) systems and, more particularly, to systems and methods that predict performance of DSL service on arbitrary telephone loops.
B. Description of Related Art
Digital subscriber line (DSL) technologies use sophisticated modulation schemes to pack data onto existing copper telephone lines (i.e., plain old telephone service (POTS) lines). DSL technologies are sometimes referred to as last-mile technologies because they are used only for connections from a central office to a home or office, not between central offices.
It is envisioned that DSL service will be provided over a majority of the existing copper telephone lines or loops. One of the more difficult aspects of providing DSL service is predicting which customer loops cannot support the DSL service, which customer loops can support the service, and predicting what level of service (e.g., data rates) these latter loops can support. Conventional systems roughly estimate the level of service supportable by these loops by performing metallic line tests to estimate the lengths of the loops. These tests, however, cannot determine the wire gauges of the loops or the presence of bridged taps. Both of these factors can have a major impact on DSL performance, leading to possibly inaccurate estimations by the conventional systems.
As a result, a need exists for a method that more accurately predicts the level of DSL performance supportable by existing copper loops.